Grinding machine and wheel dresser therefor



April 1963 o. CARLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed 001:. 18,1960 4 Sheets-Sheet 1 FIG. I

INVENTORS LEONARD 0-. CARLSEN y THOMAS A. DEPREZ ATTORNEY April 3, 1963L. o. CAYRLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct. 18, 19604 Sheets-Sheet 2 FIG. 2

M5 T W! I g2 u Hm! 40 II I ul 38 4 I l 44..

'H"" r M8 8 April 1963 1.. o. CARLSEN ETAL 3,086,508-

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct; 18',1960 4 Sheets-Sheet 3 FIG. 5 am April 1963 L. o. CARLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct. 18, 19604 Sheets-Sheet 4 .FIG. 6

FIG. 7

2 & on 7 241 no: 7A-25o 2' F|G.8 I f 2 5a- 2 4 243 234 23s in. W 232 253I United States Patent Ofiice 3,086,508 Patented Apr. 23, 1963 11Claims. (Cl. 12511) The present invention relates to a cutter sharpeningmachine or like machine employing a grinding wheel and a wheel dressertherefor, and is a division of our copending application Serial No.63,414, filed October 18,1960.

A machine according to the invention has a grinding wheel with a conicalface, a dresser wheel whose axis is approximately parallel to a coneelement of said conical face, said dresser wheel having a cylindricalsurface for dressing said conical face and a surface of decreasingradius and concave profile for dressing an edge radius on the grindingwheel, means for guiding the dresser wheel for motion (a) in a radialdirection toward and away from said cone element to dress said edgeradius with said surface to concave profile and return, and for motion(b) approximately in the direction of the axis of the dresser wheel todress said conical face with said cylindrical surface.

In the preferred embodiment of the invention shown in the accompanyingdrawings:

FIGS. 1 and 2 are respectively side and front views of the machine;

FIG. 3 is a section in plane 3'3 of FIG. 4;

FIGS. 4 and 5 are vertical sections respectively in planes 4--4 and 5-5of FIG. -1;

FIG. 6 is a front view of the wheel dresser mechanism, parts of whichappear on a smaller scale in FIGS. 1 and 2;

FIGS. 7 and 8 are sectional views taken respectively in planes 77 and 88of FIG. 6.

Referring to FIGS. 1 and 2, the machine comprises a frame 30 on which agrinding wheel W is mounted for reciprocation longitudinally, asindicated by arrow 31, to cause its conical face 32 to traversesharpening plane 33 of a cutter C to be sharpened, which is alsosupported by the frame. The mounting of the wheel includes a column 36adjustable laterally of the frame, as indicated by arrow 37, and abracket 39 movable vertically on the column, as indicated by arrow 38. Awheel head 43 .is adjustable as indicated by arrow 45 in a directionperpendicular to both axis 42 and the wheel rotation axis, designated44. The wheel is driven by motor 40 carried by the head 43.

A cutter head bracket 46 is mounted on the frame, beneath the grindingwheel, for adjustment about transverse axis 47. On this bracket a cutterhead 48 is pivotally adjustable about an axis 49 which is perpendicularto axis 47. A housing 51, for spindle 52 which supports the cutter C, isadjustable in the head 48 in the direction of the spindle axis 53 andalso angularly about that axis.

The machine is adapted to sharpen either right or left hand cutters bymounting the grinding wheel either in the position shown at W in fulllines or at W in broken lines in FIG. 2, and by adjusting the wheel headand support, 43, 41, about axis 42 so that the wheel axis is in position44 or 44. In these respective positions the conical face 32 of the wheeltraverses sharpening planes 54 and 54' as the wheel strokes back andforth in direction 31, these planes being parallel to axis 42. In bothcases the periphery of the wheel traverses a two nuts to urge themapart.

plane, designated 55, which is perpendicular to planes 54, 5 4 andparallel to axis 42.

FIGS. 3 and 4 show the mechanism by which the wheel feed and returnmotions 45, FIG. 2, are accomplished. In the wheel head 43 is journaledthe spindle 171 on either end of which the wheel W may be mounted. Thewheel head is supported on ball-sleeve bearing 172 for motion in wheelhead support 41 in direction 45, perpendicular to axis 44 of thespindle. Prior to each wheel dressing operation a ratchet mechanism isoperated to lower the wheel in direction 45 by a predetermined distance.This ratchet mechanism comprises a piston 173 movable in one directionin a cylinder in the wheel head support by hydraulic pressure applied tocylinder chamber 174, and in the return direction by a spring 175 whenthis pressure is released. A pawl 176 pivoted at 177 to the piston isurged by a spring 178 into engagement with a ratchet wheel 179. Uponreturn motion the pawl engages a stud 181 and is thereby pivoted out ofengagement with the wheel 17-9. The latter has secured thereto a nut 182which is threaded onto a screw 183 secured to the wheel head 43. Toeliminate backlash between the nut and screw, and to frictionallyprevent unintentional retrograde motion of the ratchet wheel when thepawl is released, a nut 184 also threaded to the screw is keyed to thenut 182 for axial motion relative thereto, and a spring washer 185 isdisposed between the When the limit of downward wheel feed has beenreached, and the wheel W is to be replaced, upward return motion of thewheel head 43 may be effected by manually turning the ratchet wheel andnut assembly by means of a wrench applied to socket 186 of the ratchetwheel.

FIG. 5 illustrates the mechanism for effecting the motions 38, FIG. 2,for vertical adjustment of the grinding wheel W and for elevating it topermit indexing the cutter, mounting and removal of the cutter, anddressing of the wheel. A cylinder member 191 is secured to the column 36and slidable in the cylinder bore there is a piston 192 having at itsupper end a flanged nut 193 adapted to seat on a ring 194 supported bycylinder head 195. The nut is threaded to a screw 196 journaled forrotation in a radial and axial thrust bearing 197 secured to the bracket39. On screw 196 is a bevel gear 198 meshing with a pinion 199 rotatablein the bracket. By manual rotation of the pinion, by means of a suitablewrench, the bracket may be raised or lowered to bring the periphery ofthe wheel into tangency with reference plane 55, FIGS. 1 and -2. A cover201 which telescopes over the column 36, is movable as a unit with thebracket. An annular piston 202 in the cylinder is slidable on the piston192 and is adapted for abutment by shoulder 203 of the latter. Slidablein the piston 192 is a tappet 204 urged downwardly relative to thepiston by a spring 205, the bottom of the tappet being adapted to rideon a cam or ring on a shaft 206 which is rotatable and also axiallyshiftable in the column 36. The tappet is shown as seating on a ring 207concentric with shaft 206, but by manually-effected axial shifting ofthe shaft, to the left, a cam 208 secured on the shaft may be broughtbeneath the tappet. Also secured to the shaft is a ratchet wheel 209.

By application of hydraulic pressure through lines 210 and 211 tocylinder chambers 212 and 213, piston 202 is held in its down limitposition shown, and piston 192 is elevated until its shoulder 203 abutspiston 202. This elevates the bracket 39 to indexing position, whereinthe wheel W is clear of the cutter being sharpened. By release ofpressure from line 210, pressure in chamber 213 will further raise thepiston 192 and cause it to lift the piston 202 into abutment withcylinder head 195. This elevates the bracket 39 to the position whereina a cutter may be loaded or unloaded and wherein the wheel W is dressed.From either elevated position the piston 192 is lowered by placing line211 on exhaust and applying pressure through line 214 to chamber 215.Lowering is rapid throughout most of the stroke because spring 205 haslowered the tappet 204 relative to the piston, so that land 216 of thetappet allows fluid exhaust through port 217 in the piston and passage218 to line 211, but is slowed when the tappet abuts and is arrested byring 207 (or cam 208). This shifts the piston relative to the land, toclose off port 217 and cause the exhaust from chamber 213 to be througha flow restrictor 219. A check valve 221 is closed throughout loweringof the piston but is open while the piston is being elevated.

Ring 2117 is utilized to limit the down motion of the grinding wheel inthe case of cutters to be sharpened toa constant depth. In otherinstances, where different blades around the cutter are to be ground todifferent depth, a cam 298 especially designed for such cutter isutilized. By means of ratchet wheel 209 and an actuator for it operatingin time with the index means for the cutter spindle, the rotation of thecam 208 is correlated with indexing rotation of the cutter. The ratchetwheel actuator may be generally similar to that shown in FIG. 3, and behydraulically connected to the actuating piston of the cutter spindleindex mechanism, described hereinafter.

The dressing mechanism for the grinding wheel appears only partially inFIGS. 1 and 2, and is shown in detail in FIGS. 6 to 8. It comprises adiamond-impregnated dresser wheel 231 having a cylindrical surface 232for dressing the conical face 32 of wheel W as shown in full lines inFIG. 6 and a concavely radiused surface 233 for dressing a convex edgeradius on the wheel as shown in broken lines in the same view. Thedresser wheel is journaled for rotation in a dresser arm 234, and isdriven by a motor 235 mounted on bracket 39, the drive being through aflexible cable 236 encased in a flexible sheath 237, a bevel pinion 238journaled in arm 234, and bevel gear 239 rotatable as a unit with thewheel. Arm 234 is secured to a piston rod 241 journaled on ballsleevebearings 242 for both angular and axial motion in a cylinder housing243. A piston 244 afiixed to the rod is movable axially by means ofhydraulic pressure alternately applied to chambers 245 and 246. Thismotion is limited by abutment of end flange 247 of the piston rod withstop 248 and cylinder head 249.

An internal gear segment 251 secured to the piston rod 241 meshes with apinion 252 rotatable on a stub shaft 253 affixed to the cylinder housing243. Also meshing with the pinion is a rack 254 on the rod of a piston255. The latter is reciprocated by alternate application of hydraulicpressure to chambers 250 and 257 to respectively swing the arm 234 upand down about axis 256 of piston rod 241, the limit positions beingdetermined by abutment of the piston 255 with cylinder heads 25S and259.

The dressing is accomplished by the two wheels W and 231 being motordriven, at different peripheral speeds. To begin dressing the wheelstroking mechanism is operated to move the wheel W in direction 31, FIG.1, into the same vertical plane as the dressing wheel 231 and the wheelW is raised as a unit with bracket 39 to dressing position by hydraulicpressure applied through lines 210 and 211, FIG. 5. By application ofpressure to chamber 257, FIG. 7, the dresser wheel 231 is lowered.Ratchet wheel 179, FIG. 3, is advanced one pitch by application ofpressure to chamber 174, to feed the Wheel downwardly in direction 45,FIGS. 2 and 4; and the dresser wheel 231, in its lower, broken lineposition in FIGS. 6 and 7, is shifted to the left in FIGS. 6 and 8 bypressure applied to chamber 246, to thereby dress the edge radius of thewheel W. This motion is such that the dresser wheel axis 261 as viewedin FIG. 6 shifts from the right side of the vertical plane through axis42 to position 261 to the left of said plane. The dresser wheel is thenreturned, to the right, by pressure applied to chamber 245, and then israised, by pressure applied to chamber 259, to dress the conical surface32 of wheel W. Pressure is released from chamber 174, FIG. 3, causingreset motion of pawl 176, and the bracket 39 is lowered by piston 192 tobring the wheel W to the reference plane 55, FIG. 1. When the wheel isin position W, FIGS. 2 and 6 for sharpening a left hand cutter, thedressing action is the same, except that application of pressure tochambers 245 and 246, FIG. 8, is reversed, so that the edge radius ofthe grinding wheel is dressed by motion of the dresser wheel to theright. That is, as viewed in FIG. 6, the dresser wheel axis shifts fromposition 261 to position 261.

At the conclusion of dressing the bracket 39 and wheel W are lowered togrinding position, wherein the wheel periphery touches plane 55, bypiston 192, FIG. 5.

Having now described our improved machine, and its operation, we claimas our invention:

1. A machine adapted to support a substantially frusto-conical grindingwheel in either of two positions, with the wheel axis in one positionintersecting the line of the wheel axis in the other position, and withthe conical surface of the wheel in said two positions intersecting inparallel lines the common plane of the lines of the wheel axis in saidtwo positions, the machine supporting a dresser wheel with its axis in aplane parallel to and between said lines, said dresser wheel having acylindrical surface for dressing the conical face of the grinding wheeland a surface of decreasing radius and concave profile for dressing anedge radius on the grinding wheel, means for guiding the dresser wheelfor motion (a) of its axis substantially in said common plane andperpendicular to the dresser wheel axis to dress the edge of thegrinding wheel, in either position of the latter, with said surface ofconcave profile and to bring said cylindrical surface substantially toeither one of said parallel lines of intersection, and for motion (b)approximately in the direction of the axis of the dresser wheel to dressthe conical surface of the grinding wheel with said cylindrical surface.

2. A machine according to claim 1 in which there are means to limit thestroke of motion (a) in both directions, the dresser wheel at one limitbeing positioned to dress the edge radius of the grinding wheel in oneposition of the latter and the conical face of the grinding Wheel in theother position thereof, and the dresser wheel at the opposite limitbeing positioned to dress the edge radius of the grinding wheel in saidother position and the conical face of the grinding wheel in said oneposition.

3. A machine adapted to support a substantially frustoconical grindingwheel in either of two positions, with the wheel axis in one positionintersecting the line of the wheel axis in the other position, and withthe conical surface of the wheel in said two positions intersecting inparallel lines the common plane of the lines of the wheel axis in saidtwo positions, the machine supporting a dresser wheel with its axis in aplane parallel to and between said lines, means for guiding the dresserwheel for motion (a) of its axis substantially in said common plane andperpendicular to the dresser wheel axis to bring the periphery of thewheel to either one of said lines, and for motion (b) approximately inthe direction of the axis of the dresser wheel to dress the conicalsurface of the grinding wheel.

4. A machine according to claim 3 in which there are means to limit thestroke of motion (a) in both directions, the periphery of the dresserwheel at one limit being positioned to dress the grinding wheel in oneposition of the latter and at the other limit being positioned to dressthe grinding wheel in the other position thereof.

5. A dresser for a grinding wheel comprising a housing having twocylinders with their axes at right angles, a first piston reciprocabieand angular movable in one cylinder, said piston having an arm thereoncarrying a dresser tool, a second piston reciprocable in the secondcylinder, and gearing connecting said pistons to cause the first pistonto be oscillated angularly by and upon reciprocation of the secondpiston.

6. A dresser according to claim 5 in which said gearing comprises a rackcarried by the second piston, a pinion meshing with the rack andsupported for rotation in the housing, and a gear meshing with thepinion and carried by the first piston.

7. A machine having a grinding wheel with a conical face, a dresserwheel whose axis is approximately parallel to a cone element of saidconical face, said dresser wheel having a cylindrical surface fordressing said conical face and a surface of decreasing radius andconcave profile for dressing an edge radius on the grinding wheel, meansfor guiding the dresser wheel for motion (a) in a radial directiontoward and away from said cone element to dress said edge radius withsaid surface of concave profile and return, and for motion (b)approximately in the direction of the axis of the dresser wheel to dresssaid conical face with said cylindrical surface.

8. A machine according to claim 7 in which said motion (b) is in an arctangent to the axis of the dresser wheel about a pivot axis remote fromthe dresser wheel and perpendicular to said cone element and to therotation axis of the dresser wheel.

9. A machine according to claim 8 in which the means for guiding thedresser wheel comprise a housing, an arm movable angularly on thehousing about said pivot axis for efiecting said motion (b), and saidarm being movable relative to said housing along said pivot axis forefiecting said motion (a).

10. A machine according to claim 9 in which there is a fluid actuatedpiston which carries said arm and is reciprocable in a cylinder in thehousing for effecting said motion (a), the axis of said cylinderconstituting the pivot axis of the arm, and there is a second fluidactuated piston reciprocable in said housing and connected to the firstpiston for oscillating it about said pivot axis for effecting saidmotion (b).

11. A machine according to claim 10 in which the connection between thepistons comprises a rack carried by the second piston, a pinion meshingwith the rack and supported for rotation 'by the housing, and a gearmeshing with the pinion and carried by the first piston.

References Cited in the file of this patent UNITED STATES PATENTS1,467,985 Schuvr Sept. 11, 1923 2,067,531 Indge Jan. 12, 1937 2,086,750.Tanner July 13, 1937 2,171,902 1 Wood Sept. 5, 1939 2,323,401 JohnsonJuly 6, 1943 2,565,013 Bargren Aug. 21, 1951 2,697,426 Price et al. Dec.21, 1954 2,792,672 Carlsen et al. May 21, 1957 2,826,008 Dunn Mar. 11,1958 2,963,017 Norel et al. Dec. 6, 1960 2,972,343 Dunn Feb. 21, 1961

7. A MACHINE HAVING A GRINDING WHEEL WITH A CONICAL FACE, A DRESSERWHEEL WHOSE AXIS IS APPROXIMATELY PARALLEL TO A CONE ELEMENT OF SAIDCONICAL FACE, SAID DRESSER WHEEL HAVING A CYLINDRICAL SURFACE FORDRESSING SAID CONICAL FACE AND A SURFACE OF DECREASING RADIUS ANDCONCAVE PROFILE FOR DRESSING AN EDGE RADIUS ON THE GRINDING WHEEL, MEANSFOR GUIDING THE DRESSER WHEEL FOR MOTION (A) IN A RADIAL DIRECTIONTOWARD AND AWAY FROM SAID CONE ELEMENT TO DRESS SAID EDGE RADIUS WITHSAID SURFACE OF CONCAVE PROFILE AND RETURN, AND FOR MOTION (B)APPROXIMATELY IN THE DIRECTION OF THE AXIS OF THE DRESSER WHEEL TO DRESSSAID CONICAL FACE WITH SAID CYLINDRICAL SURFACE.